Endoscopic surgical instrument

ABSTRACT

An improved electrode apparatus for use with an endoscopic surgical instrument provides an adjustable volume of tissue ablation and may be used with an RF energy source in either monopolar or bipolar output mode. The electrode apparatus may be used in any endoscopic surgical application, and provides a new method for any endoscopic treatment involving soft tissue ablation, including hysteroscopic and laparoscopic treatment of uterine fibroids/myomas.

RELATED CASES

This is a continuation-in-part of application Ser. No. 08/259,712 filedon Jun. 14, 1994, now U.S. Pat. No. 5,562,703, which is acontinuation-in-part of Ser. No. 08/025,003, filed Mar. 2, 1993, nowabandoned, which is a continuation-in-part of Ser. No. 07/779,108, filedOct. 18, 1991 (now U.S. Pat. No. 5,322,503).

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a surgical instrument and more particularly toan instrument with the capability for continuous irrigation andevacuation of fluid into and out from a body cavity of a patient duringLaparoscopic or Endoscopic surgical procedures, and for the simultaneousmeasurement of tissue impedance and the ablation of tissue with fixed orretractable electrodes using R.F. energy.

2. Brief Description of the Prior Art

Laparoscopic/endoscopic surgical procedure allows a surgeon to seeinside the body cavity of a patient without the necessity of largeincisions. This reduces the chances of infection and other complicationsrelated to large incisions. The endoscope further allows the surgeon tomanipulate microsurgical instruments without impeding the surgeon's viewof the area under consideration.

During these surgical procedures it is desirable for as few lines aspossible to enter the body of the patient. This reduces the size of theincision the surgeon needs to make. It follows from this that thegreater the number of functions provided by a single instrument or thegreater the number of instruments able to be passed through a singleline entering the patient's body, the better.

Furthermore, in certain procedures it may be desirable to irrigate thearea under consideration. This in turn necessitates the evacuation ofthe irrigation fluid or, when bleeding has occurred, the blood or smokeor tissue residue generated by the surgical procedure.

From what has been said above it should be apparent that it ispreferable for both irrigation and evacuation to be conducted along asingle conduit which, also, acts as an access line for surgicalinstruments.

A typical device which is used in endoscopic procedures is anelectrosurgical probe. Typically such a probe will comprise a radiofrequency (i.e. R.F.) energy conductive tube covered with a dielectricmaterial such as polyolefin or Teflon. At one end, for conveniencecalled the operational end, each probe could have any one of a number offunctionally shaped monopolar or bipolar electrodes. In addition a probecould have its end formed specifically for irrigation and/or evacuation.

Monopolar and bipolar electrode probes are known in the prior art.Monopolar electrode probes include a single active electrode which issurgically introduced into a body cavity and engagable with andinsertable into a tissue portion of the cavity. A passive electrode isattached to the outer body surface of the patient, e.g. typically aconducting plate is adhesively attached to the patient's leg. The bodyof the patient serves to complete the electrical circuit. Tissueablation and coagulation is achieved by introducing sufficient powerinto the active electrode. Bipolar electrode probes include both activeand passive electrodes which are similarly introduced together into thebody cavity and are spaced apart from each other by a predetermineddistance. Each electrode is engageable with and insertable into thetissue portion. Thus, the electrical circuit is completed by the bodytissue disposed between the active and the passive electrodes and onlythe body tissue disposed between the two electrodes get coagulated.

Furthermore, any valves controlling the evacuation and irrigationprocedures should be constructed so as to minimize the possibility ofthe valve malfunctions if, for example, any tissue or blood coagulatesaround their moving parts. Similarly if any of the instrumentation is tobe reusable, such instrumentation, including the valves, should becapable of being efficiently cleaned by, for example, flushing.

U.S. Pat. No. 4,668,215 (Allgood) discloses a valve for switchingbetween an evacuation and an irrigation conduit and allowing both suchevacuation and irrigation to be done via a single line entering thepatient. The mechanism for switching between the irrigation, evacuationand closed configurations is by means of a L-valve or T-valve. Thispatent, in another embodiment thereof, further provides for a pistonvalve for making an on-off connection between an evacuation port and theline leading into the patient.

The L- and T-valves have the disadvantage that they must be manipulatedby rotation by the surgeon, usually using his/her free hand. The pistonvalve disclosed in this patent has the disadvantage that it has manyareas where blood and tissue accumulation and coagulation can occurwhich may result in the malfunctioning of the valve. In addition, thepiston valve has numerous "dead" areas where fluid flow would not occur.This precludes the device from being effectively cleaned by commonlyused flushing techniques. Finally, the Allgood patent does not disclosea single body for housing an evacuation/irrigation control valvetogether with a housing for laparoscopic and microsurgicalinstrumentation.

A surgical valve that the applicant is aware of is the piston valveillustrated in FIG. 1 of the accompanying drawings.

In this valve a piston 10 is located within a cylinder 11. The piston 10can be moved along the bore of the cylinder 11 by means of a plunger 12,from a closed position (as shown) to an open position in which a conduit13 is aligned with an access port 14. This allows fluid flow along apath to or from access port 14, via conduit 13 and space 16 from or to afurther port 15. Upon release of the plunger 12 the piston 10 returns toits closed position under action of a spring 17.

This valve, although easy to use, has the disadvantage that blood andtissue accumulation occurs in space 16 and clogs both the space and thespring 17. This may result in undesirable over-evacuation or irrigationof the patient during surgical procedures.

OBJECTS OF THE INVENTION

It is therefore an object of this invention to provide a surgicalinstrument which includes control means to allow for the continuousirrigation and evacuation of a body cavity of a patient duringmicrosurgical procedures, with both irrigation and evacuation beingperformed along a single line into the patient. The instrument shouldalso act as a mounting for electrosurgical probes and microsurgicalinstruments.

A further object of the invention is to provide a configuration for aninstrument which, depending on the material it is constructed of, can beboth disposable and non-disposable in the event that the instrument is"reusable" or "reposable" it is an object of the invention to providethe instrument with conduits, access ports and valves which can easilybe cleaned by means of commonly used cleaning techniques andconventional sterilization methods.

It is another object of the invention to provide an electrosurgicalinstrument with fixed or retractable RF electrodes having the capabilityto simultaneously perform controlled ablation of tissue usingmonopolar/bipolar R.F. energy and precise measurement of tissueimpedance.

An object of the present invention is to provide an adjustable area oftissue coagulation, which may be larger or smaller than the size of theprobe enclosing the electrodes. A further object is to provide multiplebipolar electrodes to allow a larger zone of coagulation. The spacing ofthe multiple electrodes may be adjusted for larger or smallercoagulation zones.

Another object of the present invention is to provide a singleconnecting cable system for use with an RF energy source and an RFelectrode means whereby either the monopolar or bipolar output mode fromthe energy source may be selected and used with a single RF electrodemeans. The connecting cable system permits use of the single electrodemeans for either RF output mode (monopolar or bipolar, which aretypically labelled CUT and COAG, respectively on commercially availableRF generators), and the user may elect the output mode while theelectrode means are in situ.

Still another object of the invention is to provide a method forhysteroscopic and laparoscopic treatment of uterine fibroids/myomas withmonopolar or bipolar electrosurgical instrumentation for controlledablation of tissue.

SUMMARY OF THE INVENTION

According to this invention, an endoscopic surgical instrument comprisesan irrigation and an evacuation port, each port being connected throughindependent valves to a single access conduit, a probe connector locatedat one end of the access conduit, the probe connector being forreceiving and retaining a hollow surgical probe; and a monopolar orbipolar radio frequency connector which exits into the access conduit insuch a manner so as to make radio frequency connection with a probereceived by the probe connector.

Preferably the connector for receiving an end, for convenience calledthe locating end, of the probe would be in the form of a receiving borein the access conduit which would include a plurality of O-rings whichprovide a fluid-tight seal around the locating end of the probe. TheseO-rings also function to retain the probe in the receiving port whileallowing the probe to be rotated. In one embodiment of the invention,the O-rings are, instead of being located within the receiving bore ofthe access conduit, located about the locating end of the probe.

This invention also provides for a valve, for use as either anevacuation or an irrigation valve, the valve comprising a housing, anactivator connected to the housing, at least a first and a second valveaccess conduit, both of which exit into the housing and a fluidimpervious seal mounted within the housing such that activation of theactivator causes the first valve conduit to move axially relative to theseal and the second valve conduit such that the seal is disengaged andthe conduits are placed in direct fluid communication with each other.

Typically, the instrument of the invention would contain two of theabove described valves. One valve would act as an evacuator controlwhile the other valve would act as an irrigation control. Both valvescommunicate into a single access conduit which, when the instrument isin use, continuously flows into the patient via the receiving bore andthe hollow interior of the electrostatic probe.

Preferably the endoscopic surgical instrument of the invention is in theform of a pistol with the "barrel" portion thereof having, at one endthereof, the receiving bore for the locating end of the endoscopic probeand, at the other end thereof, the access port for the microsurgicalinstruments and endoscopes.

The valves for controlling the evacuation and irrigation procedures maybe mounted in the "handle" portion of the pistol-shaped instrument. Thevalves may be mounted alongside one another in the handle portion andmay protrude therefrom to allow finger control by the surgeon using theinstrument.

In one alternate embodiment of the invention the surgical instrumentincludes a housing, a single access conduit formed in the housing, anirrigation port and an evacuation port, each port being connectedthrough independent valves to the single access conduit. The singleaccess conduit has a first end, and a second end which is terminated inan aperture formed in the housing. A closure is provided for theaperture. A viewing device, such as an endoscope, is insertable throughthe aperture and into the single access conduit. The viewing device isof sufficient length such that it is extendable slightly beyond thefirst end. A retractable electrode assembly is also insertable throughthe aperture and into the single access conduit, and is of sufficientlength such that it, too, is extendable beyond the first end. Theretractable electrode assembly, in one embodiment, includes tworetractable RF electrodes spaced apart by a predetermined width. Each RFelectrode is made from a superelastic material, e.g. typicallyNickel-Titanium (NiTi) metal, is sheathed within a guiding sheath, andis slidable within the sheath such that it is extendable beyond and.retractable completely within the sheath. Also, each electrode isconnected to a mechanism, operable by a surgeon, for moving theelectrode within the sheath. Each electrode is extendable beyond itsguiding sheath by a variable length and at a predetermined angle from alongitudinal axis of the single access conduit. Further, each electrodeis electrically communicative with means for supplying R.F. energy andmeans for measuring impedance continuously on a realtime basis.

These and other objects and advantages of the present invention will nodoubt become apparent to those skilled in the art after having read thefollowing detailed description of the preferred embodiment which isillustrated in the several figures of the drawing.

IN THE DRAWINGS

In the following drawings:

FIG. 1 is a partial sectional elevation through a prior art pistonvalve;

FIG. 2 is a diagrammatic section through a semi-exploded elevation ofone embodiment of the endoscopic surgical instrument of the invention;

FIGS. 3A-3B illustrate a tricuspid valved access port in plan (a) andelevation (b) views;

FIG. 4A is a section through a receiving bore of the instrumentillustrating one way of locating a probe in the bore;

FIG. 4B is an illustration of a probe for use with the connector shownin FIG. 4A;

FIG. 5A is a section through a similar receiving bore showing adifferent way of locating a probe in the bore;

FIG. 5B is an illustration of a probe for use with the connector of FIG.5A;

FIG. 6 is a side view illustrating in (a)-(i) various: electrostaticprobe operational ends;

FIG. 7 is a section through a valve according to the invention with thevalve being in the shut position;

FIG. 8 is the valve of FIG. 7 in the open position;

FIG. 9 is a partial section through a different type of valve alsosuitable for use in the instrument of the invention;

FIGS. 10, 11, 12 and 13 are diagrammatic illustrations: showing variousconfigurations of valve operating buttons and triggers;

FIG. 14 is an exploded view of an alternative embodiment of the surgicalinstrument of the invention illustrating a disposable valve cartridge;

FIG. 15 is a cross section through the disposable valve cartridgeillustrated in FIG. 14;

FIG. 16 is a partially sectioned view of another type of valve which canbe used in the surgical instrument of the invention;

FIG. 17 is a perspective view of an alternate embodiment of theendoscopic surgical instrument having generally similar valves, asillustrated in FIG. 7-8, and a retractable electrode assembly havingbipolar RF electrodes in electrical communication with a R.F. energysource and a tissue impedance monitoring device;

FIG. 18 is a partial sectional view taken along the line 18--18 of FIG.17;

FIG. 19 is a view taken along the line 19--19 of FIG. 17;

FIG. 20 is a side elevation view of the retractable electrode assemblyshown in FIG. 17;

FIG. 21 is an enlarged view of the tip of the retractable electrodeassembly shown in FIG. 17;

FIGS. 22A-22H illustrate alternate electrode configurations for theretractable electrode assembly shown in FIG. 17 and 20;

FIG. 23 is an enlarged view of the tip of the retractable electrodeshown in FIG. 22D-22F; and

FIG. 24 is an alternate embodiment of the present invention including aretractable electrode assembly having a variable angle controlmechanism.

FIG. 25(a) is an illustration of the use of multiple electrodes orientedat an angle theta;

FIG. 25(b) shows an end view of the electrodes of FIG. 25(a) providing arectangular pattern;

FIG. 25(c) shows a view similar to FIG. 25(b), in which two electrodesare used;

FIG. 25(d) illustrates the use of three electrodes for obtaining anapproximate circular coagulation pattern;

FIG. 25(e) illustrates the use of four electrodes to achieve anapproximate circular coagulation pattern;

FIG. 25(f) shows the use of nine electrodes to achieve an improvedcircular pattern;

FIG. 26(a) illustrates the use of superelastic metal electrodes toachieve an adjustable pattern;

FIG. 26(b) further clarifies the configuration of FIG. 26(a);

FIG. 27 illustrates the use of a frusto-conical extension for deflectingthe electrodes to achieve an adjustable zone of coagulation; and

FIG. 28 shows a connecting cable system for selectively applying bipolaror monopolar RF power to the electrodes.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In FIG. 2 of the accompanying drawings, the endoscopic surgicalinstrument of the invention is generally indicated as 20. The instrument20 is shown to include an irrigation port 21 and an evacuation port 22.Each port, 21 and 22, is connected through independent valves 23 and 24,respectively, to a single access conduit 25. The connection between thevalves 23 and 24 and conduit 25 is along connector tubes 23a and 24a.

The access conduit 25 leads from the valves and their respective valveconduits to a probe connector 26. This probe connector 26 is designed toreceive one end, the locating end 27, of a surgical probe 28 which wouldbe used during microsurgical procedures. The connection 26 is describedin more detail with reference to FIGS. 4 and 5 hereafter.

At or near the probe connector 26, a monopolar/bipolar radio frequencyconnector 29 is located. As illustrated, this is in the form of a R.F.connector. The advantage of a R.F. connector is that it is an industrystandard and can be used for connecting the instrument 20 to standardR.F. energy sources marketed by a number of different manufacturers.

The radio frequency connector 29 exits into the access conduit 25 whereit makes connection with a point 30, on the locating end 27 of a probe28 received by the probe connector 26.

The surgical instrument 20 also includes a port 31 which allows thesurgeon to insert microsurgical instrumentation and viewing devicesalong the access conduit 25 and the bore of the hollow probe 28 to exitfrom the end 32 thereof. The port 31 should provide a fluid-tight sealwhen no microsurgical instrumentation is being used with the surgicalinstrument 20. This will prevent fluid, which may be moving along theaccess conduit 25 to or from the patient, from leaking.

Typically, the access port 31 is in the form of a commercially availabletricuspid valve as illustrated in FIGS. 3(a) and (b). In these figures,the valve 31 is shown as being constituted by three segments 32 which inplan view are wedge-shaped and which together form the disc shapedsealing portion of the valve. The segments 32 are held together by meansof a circumferential ring 33 which biases the three segments 32 togetherto form a fluid-tight seal. In use, the microsurgical instrumentationare inserted through the valve at a point 34 where the apexes of thesegments 32 come together. This insertion forces the elements of thevalve apart to allow ingress of the microsurgical instrumentation. Theeffect thereof is shown in broken lines in FIG. 3(b). When theinstrumentation is removed from the valve 31, the segments 32 are pulledtogether to form the seal.

In FIG. 4 the probe connector 26 is shown to be constituted by areceiving bore which is coaxial with the fluid access conduit 25. Inpractice, the diameter of this bore would be the same as that of theaccess conduit 25 and would be sized to receive the locating end 27 ofthe probe 28 in a relatively close fit. Within the bore forming theprobe connector, a plurality, typically two, O-rings 36 are located.When the locating end 27 is inserted into the bore 26 these O-ringsprovide a snug, fluid-tight seal about the end 27. Once the locating end27 of the probe is received within the bore 26 it is capable of beingrotated about its longitudinal axis, by means of a knurled rotation knob37 located between the locating end 27 and the operational end 32 of theprobe 28.

The probe 28 would typically be made of a electrostatic conductivematerial coated with a non-conductive material such as heat shrinkpolyolefin or Teflon. Electrostatic/radio frequency energy is passedalong the probe 28 from the radio frequency connector 29 viaelectrostatically conductive plates 38 located within the bore of theprobe connector 26 and onto the end 30 of the probe 28. The end 30 is sodesigned such that when the locating end 27 of the probe is received bythe probe connector 26, electrostatic connection is made between theplate 38 and the connector 30. This allows the surgeon to pass energyinto the patient being operated on.

An alternative radio frequency connector is illustrated in FIG. 5. Inthis case, the R.F. connector 29 exits into the bore 26 in the form of apin 39. In the conductive end 30 of the probe 28 an L-shaped slot 40 isformed. As the probe 28 is inserted into the receiving bore 26, the pin39 engages the axially-orientated leg 41 of the L-shaped slot 40. Whenthe probe can be inserted no further along the bore it is twisted, inthis case in an anti-clockwise direction, such that the pin 39 and theaxially transverse leg 42 of the L-shaped slot 40 engage each other tolock the probe 28 into position. In this embodiment the probe 28 cannotbe rotated by means of the knurled knob 37.

FIG. 5 further illustrates an alternative positioning of the O-rings 36.In this case they are located on the locating end 27 of the probe 28.

From FIGS. 4 and 5, although not shown, it will be apparent that thediameter of the operational shank 28a of the probe 28 can be variable.Typically, the probe, as shown, would have a diameter of 5 mm. Thisdiameter can, however, be increased to 10 mm which would be close to thediameter of the locating end 27 of the probe, as well as that of theinternal bore diameter of the access conduit 25. The advantage of 10 mmdiameter probes is that the evacuation of removed tissue and objectssuch as the gall-stones can be more effectively achieved. Obviously,when the bore of the operating shank 28a of the probe, the locating end27 and the access conduit 25 are all 10 mm in diameter, the diameter ofthe evacuation port 22 and its related valve 24 and connector tube 24amust also be 10 mm.

In FIG. 6(a) to (i), a side view of number of different electrode shapesare illustrated. It will be appreciated that the electrode tips could beeither monopolar or bipolar. In the case of bipolar electrodes, only oneelectrode is illustrated since a second electrode is fully obscured bythe visible electrode. These electrode tips would be located on theoperating end of the probe 28.

As can be seen from the figure, a number of the tips are not symmetricalabout the longitudinal axis of the probe 28. It is for this reason thatit is desirable for the probe 28 to be mounted on the instrument in sucha manner to allow for a rotation of the probe about its longitudinalaxis. As has been previously indicated, this will give the surgeon theopportunity of rotating any non-symmetrical tips, inside the patient,without having to rotate his or her wrist.

This invention extends also to an electrostatic probe 28, substantiallyas described in any of the FIGS. 4 to 6.

The details of one type of irrigation/evacuation valve are illustratedin FIGS. 7 and 8. The valve 24 indicated in both figures comprises ahousing constituted by a hollow tube 50 and an activator in the form ofa button 51 formed integrally with the tube 50. A fluid impervious seal52 is located within the tube 50. Referring specifically to FIG. 7, inwhich the valve is shown in the shut position, it can be seen that theseal 52 lies between a first valve conduit 53 which leads to theevacuation port 22 (not shown) and a second valve conduit in the form ofconnector tube 24a which leads into the primary access conduit 25 of thesurgical instrument. In effect, the seal 52 prevents the conduits 53 and24a from being in communication with each other.

The first valve conduit 53 is mounted onto the wall of the tube 50 andopens into the interior of the tube 50 through a hole 54. Between theseal 52 and the button portion 51 of a tube 50, a spring 55 is located.On the side of the seal 52, opposite to which the spring is located, atubular insert 56 is located. This tubular insert has a snug butslidable fit over the outer wall of the second valve conduit 24a as wellas a tight, fluid impervious fit into the inner bore of the tube 50.This tube 56 acts as a stop which prevents the spring 55 from pushingthe seal 52 out of the hollow tube 50.

To open the valve, as is illustrated in FIG. 8, an activating force,applied along a line F to the button 51, will cause the button to movefrom the position indicated in broken lines to the illustratedopen-valve position. As the button moves, so does the hollow tube 50,taking the first valve conduit 53 along with it. In addition, theleading edge 57 of the second valve conduit 24a bears against the seal52 causing the seal to move relatively to the tube 50. This in turndisengages the seal from sealing the hole 54 in the wall of the tube 50.The movement of the first valve conduit 53, relative to the second valveconduit 24a, places the respective openings 54 and 58 of these twoconduits in fluid communication with each other thereby allowing anunobstructed fluid flow along both access conduits.

Upon release of the force on the button 51, the bias of the spring 55will return the valve to its shut position.

It is evident from the construction of the valves illustrated in FIGS. 7and 8 that they can be readily cleaned by commonly used cleaning such asflushing. In addition, the valves have almost no areas where blood andtissue accumulation and coagulation can occur, and if such accumulationand coagulation does occur the valves cannot be jammed in the openposition. This is because the spring biasing the valve into its closedposition is located in an effectively sealed area. Furthermore thesevalves have been tested to a pressure of up to 100 psi without theintegrity of the valve seal being adversely affected.

An alternative form of valve, to that illustrated in FIGS. 7 and 8above, is shown in FIG. 9. In the figure the valve is shown to include agenerally cylindrical valve body 60, an activating button 61 and aplunger 62. A hollow bore runs down the center of the valve body 60 andcontains the valve seal 63. The valve seal 63 is made up of a circularwasher 63a and a sealing O-ring 63b and is screwed onto the bottom ofplunger 62. The valve seal 63 is biased into its illustrated sealingposition by means of a spring 64 located in the bottom part of the valvebody 60.

To open the valve, the button 61 is depressed so that the plunger 62forces the valve seal 63 downwards against the bias of the spring 64 toa position shown in broken lines 63', in the figure. As a result, afluid path, indicated by arrows 65, is opened between an upper pair ofcutouts 66 and a lower pair of cutouts 67. Each pair of cutouts opensinto the hollow bore in the center of the valve body 60 and, when thisvalve is inserted into the surgical instrument, into either anevacuation or irrigation conduit. Closure of the valve is achieved byreleasing the button and allowing the spring 64 to return the valve seal63 to the sealing position.

One advantage of this embodiment of the valve is that it is easilyremoved from and inserted into the surgical instrument of the invention.Accordingly the valve can easily be removed for cleaning or disposal andreplacement. This is further illustrated below with respect to FIG. 13.It is sufficient here to mention only that the surgical instrument isprovided with a receiving bore for each valve and that the valveincludes a plurality (in this case 3) O-rings 68 which, when the valveis inserted into its respective receiving bore, provide a number offluid tight seals against the inside of the bore.

Either of the two types of valve described in FIGS. 7 to 9 can be usedon the instrument 10. Typically one valve would act as an evacuationvalve while the other as an irrigation valve. Different types ofarrangements of valves and valve activation means are illustrated in thefollowing 4 figures.

One way of activating the valve is by means of a rocker-shaped trigger70 illustrated in FIG. 10. The trigger 70 is pivotally mounted on apoint 72 on the handle 74 of the pistol. Depressing the trigger 70 tooperate the irrigation valve 71 would not interfere with the operationof the evacuation valve 73. Similarly, operation of the trigger 70 tooperate the evacuation valve 73 would in no way effect the operation ofthe irrigation valve.

In FIG. 11 a trigger mechanism 76 is shown for operation of only one ofthe buttons. The other button 78 would be located for operation by meansof the surgeon's thumb in a position removed from the trigger 76. Thiscould, for example, be near the top end of the handle portion of theinstrument.

Yet a further positioning of the buttons 71 and 73 is indicated in FIG.12. In this instance, the buttons protrude from the top rear of thepistol handle and are located side-by-side. To prevent confusion betweenevacuation and irrigation procedures, the tops of the buttons havedifferent shapes. So, for example, the button to manipulate theevacuation valve could be concave while the button for manipulating theirrigation valve could be convexly shaped.

FIG. 13 illustrates still another arrangement of buttons and valves, inthis case an arrangement particularly suited to the valve shown in FIG.9.

In this figure only the pistol grip 90 of the surgical instrument of theinvention is shown. An irrigation port 92 and evacuation pore 94 enterthe pistol grip 90 an the bottom of its handle portion. The ports 92, 94are, in use, respectively connected to irrigation and evacuationconduits (not shown) and, to this end, suitable connectors, asillustrated, are provided.

The irrigation port 93 communicates with the main access conduit 96(referenced as 25 in FIGS. 2, 4 and 5) along an irrigation conduit 98which extends from the irrigation port 92 and into the rear of the bore100 which houses an irrigation valve 102. From there it extends alongthe bore 100 to a point near the front of the bore from where it exitsinto the body of the grip 90 to enter rear of the bore 104 which housesan evacuation valve 106. The irrigation conduit extends directly acrossthe bore 104 at this point and becomes a central conduit 108 whichcommunicates with the access conduit.

On the other hand, the evacuation port 94 communicates with anevacuation conduit 105 which extends along the pistol grip 90 directlyinto the front of the bore 104, down to the bore 104 to its rear fromwhere it exits into the central conduit 108.

In the position shown, both the irrigation and evacuation valves 102,106 respectively, are shown in the off or shut configurations andneither evacuation or irrigation can take place. Should irrigation ofthe patient be required, the dish-shaped irrigation button 110 isdepressed and the valve 102 opens (i.e. its valve seat moves to theright in the drawing) to allow irrigation fluid to pass along theirrigation conduit 98 and into the bore 104. In this bore 104 theevacuation valve 106 is in the off configuration. However, a fluid pathexists across the pair of cutouts (67 in FIG. 9) and therefore theirrigation fluid can pass through the body of the valve 106 and into thecentral conduit 108 and, from there, into the access conduit 96.

When evacuation is desired the irrigation button 110 is released and thespring associated with the irrigation valve 102 biases it into the shutor off configuration. Thereafter the flat topped evacuation button 112is depressed to open the evacuation valve 106. This allows the patientto be evacuated along the main access conduit 96, into the centralconduit 108, then from the rear to the front of the bore 104 and, fromthere, out along the evacuation conduit 105.

As has been indicated earlier, the valves 102, 106 are easily insertedinto and removed from their respective bores 100, 104. This allows thepistol grip 90 which is typically stainless steel and is reusable) to becleaned efficiently. The valves, typically being of plastic and beingdifficult to clean, can be discarded and replaced with new valves.

A variation on this theme of discardable valves is illustrated in FIG.14. In this figure the surgical instrument is shown to include a pistolgrip 120, a surgical probe 122, which can be screwed into the front ofthe pistol grip 120 and a radio frequency connector 124 which screwsinto the back of the grip 120.

The instrument also includes a removable (and disposable) valvecartridge 126. The cartridge 126 includes an irrigation pipe 128 and anevacuation pipe 130 both of which are individually operated by valves(as will be further illustrated in FIG. 15) under action ofbutton-shaped actuators 132. Both the irrigation and evacuation pipescommunicate into a single conduit (not shown) which runs down the centerof a male connector fitting 134. Where the cartridge 126 is insertedinto the grip 120 the connector 134 fits into the base of a centralconduit 136 which, in turn, opens up into the main access conduit 138 ofthe instrument. When the cartridge 126 is located in the grip 120 theactuators 132 are located directly below a pair of operating triggers140 which can be used to operate the irrigation/evacuation proceduresdescribed before.

Finally, when the cartridge 126 is in place, it is held there by meansof a retainer clip 142 which clips in behind the cartridge 126. Theretainer clip 142 has apertures 144 formed in it to allow the irrigationand evacuation pipes 128, 130 to pass through it.

Although it will be apparent that the valve types described above arealso suitable for use in the cartridge 126, a further valveconfiguration is illustrated in FIG. 15, which illustrates the cartridge126 in greater detail.

In this figure, the cartridge 126 is shown to include an irrigationconduit 150 and an evacuation conduit 152, both of which lead to acentral access conduit 154 which extends down the center of the maleconnector 134. Irrigation and evacuation procedures are controlled byirrigation and evacuation valves 156 and 158, respectively.

The irrigation valve 156 consists of a valve seal 160 mounted onto astem which is screwed into an activator button 132a. A fluid tight sealis provided for the valve 156 by an O-ring 168 mounted onto the cap132a. The valve seal 160 seals against a valve seat, formed at thejunction between the irrigation conduit 150 and the central accessconduit 154 and is held in the sealing position (as shown) by a spring162.

Access to the valve seat is through a hole 164 formed into the top (asshown in the drawing) of the cartridge 126. This hole 164 can be closedoff with a cap 166 and allows the irrigation valve 156 to be insertedinto the cartridge 126. This is done by inserting the valve seal 160 andits associated stem into the hole 164 from above and inserting thespring 162 from below. Thereafter the cap 132a can be screwed onto thestem to hold the entire valve 156 in place.

To operate an irrigation procedure the button 132a is depressed to movethe valve seal 160 clear of its seal to open a fluid path between theirrigation conduit and the central access conduit. Releasing the button132a causes the spring 162 to force the seal 160 back into its seatthereby automatically shutting the valve.

The evacuation valve 158 is of a different construction. In this valve158, the valve seal 170, in its off position as shown, seals the mouthof the evacuation conduit 152.

In operation, the seal 170 is moved under action of a plunger andevacuation button 132b from the position shown to a position 170' inwhich an end of a conduit 174, formed through the seal 170, aligns withthe central access conduit 154. At the same time the other end of theconduit 174 is aligned with the evacuation conduit 152 and evacuationcan be accomplished. By releasing the button 132b, the spring 172 biasesthe seal 170 back into its sealing position.

Assembly of this evacuation valve 158 is by inserting the entire valvemechanism into its valve bore and sealing a collar 176 in the bore.

As has been indicated with reference to FIG. 14, the cartridge 126 is ofthe disposable type and is intended for use only once. Accordingly theconsiderations of valve flushing (during cleaning) are not entirelyapplicable here.

In FIG. 16 yet another type of valve, which can be used as either anirrigation or an evacuation valve, is illustrated.

The valve, generally indicated as 180, is shown to include a hollowcylindrical valve body 182 which is sealed at its lower end by a valveseal 184 and at the other by an activator button 186. The activatorbutton 186 seals against the valve body with an O-ring 188 and isconnected to the valve seal 184 by means of a plunger 190.

To open the valve 180, the button 186 is depressed against the bias of aspring 192 to move the valve seal 184 to the position indicated inbroken lines. This opens a fluid path 194 between an opening 196 formedin the sidewall of the valve body and its lower end. Releasing thebutton 186 allows the spring 192 to force the seal 184 back into theclosed position.

One advantage of this valve is that it is very simple and inexpensive tomanufacture and can, therefore, readily be disposed of.

Finally, it will be apparent to anyone skilled in the art, that thesurgical instrument of this invention could be made from any suitablematerial. In the event than the instrument is intended for single use,plastic material could be used. Alternatively, for reusable or reposableinstrument, the instrument can be made of a more durable material.

FIG. 17 is a perspective view of an endoscopic surgical instrument 200which is an alternate embodiment of the surgical instrument 20 describedabove. FIG. 18 is a partial sectional view of a portion of theinstrument 200 taken along the line 18--18 of FIG. 17 and FIG. 19 isanother view of the instrument 200 taken as indicated by the line 19--19of FIG. 17. FIG. 20 illustrates the retractable electrode assembly 202.When viewed together, FIG. 17-20, illustrate the instrument 200including an endoscopic instrument 201, a retractable RF electrodeassembly 202, an continuous irrigation and evacuation assembly 203, aR.F. energy source 285, and a tissue impedance monitoring device 284. Itwill be appreciated that, although two retractable RF electrodes areillustrated and subsequently described, in alternate embodiments theretractable electrode assembly could have one or more than tworetractable RF electrodes. Also, although a bipolar retractable RFelectrode assembly is illustrated and subsequently described, it will beappreciated that a monopolar retractable RF electrode assembly could beused.

The assembly 203 includes a housing 210, an irrigation valve assembly214, and an evacuation valve assembly 220. The housing 210 includes anelongated portion 228 having a generally oval cross section. The portion228 includes a free tip end 230 and a secured end which is attached to ahandle portion 232. The portion 232 is held by the surgeon, and theportion 228 is surgically introduced into a body cavity (not shown) ofthe patient. A single access conduit 212 (a portion of which is bestseen in FIG. 18 and 19) is formed between an inner surface of theportion 228 and the objects carried within the portion 228. The conduit212 is disposed along the entire longitudinal length of the portion 228and is functionally similar to the conduit 25 (FIG. 2) in that itpermits the irrigation and evacuation of fluids into and out from thebody cavity into which the portion 228 is inserted. The conduit 212 isopen at the tip end 230 and can be accessed, at its opposite end, via anaperture and associated closure 226 formed in the handle portion 232.The closure 226 is in the form of a tricuspid valve and is substantiallysimilar to the valve 31 illustrated and described above (FIG. 2).

The irrigation valve and the evacuation valve assemblies 214, 220 aresubstantially similar to the irrigation and evacuation valves 23, 24described above (FIG. 2). The valve assemblies 214, 220 operate in asimilar manner to valves 23, 24 (FIG. 7, 8). Depressing the valveassemblies 214 or 220 permits the communication of fluid in a valvefirst conduit 216 (or 222) with a valve second conduit 218 (or 224).Each of the valve second conduits 218 and 224 are in fluid communicationwith the conduit 212 (in the same manner that the conduits 23a, 24a arein fluid communication with the conduit 25, FIG. 2). Thus, when thevalve assembly 214 is operated, irrigation fluid can be communicated tothe conduit 212 and out through the tip end 230, and delivered to thebody cavity. In a similar manner, fluids in the body cavity can beevacuated if the valve assembly 220 is operated.

The retractable electrode assembly 202 includes a means for guiding theangular orientation of the electrode or guide sheath 248, an endoscopesheath 238, a electrode movement mechanism 236, a tissue impedancemeasurement device 284, and a R.F. energy source 285. The sheath 248 isgenerally parallel to the scope sheath 238. The sheath 248 and thesheath 238 are each insertable into an opening of an insert flange 242,into the aperture of the handle portion 232 of the assembly 203. Thesheath 248 and the sheath 238 are insertable within the conduit 212 andare each of sufficient length such that when each is fully insertedwithin the conduit 212, each extends slightly beyond the tip end 230 ofthe cylindrical portion 228.

The endoscopic instrument or endoscope 201 is substantially similar tothe endoscope instrument described above, and can be any of a number ofdevices known in the prior art. An eyepiece 204 is shown attached to theendoscope 201. The endoscope 201 is slid into the scope sheath 238 untilthe eyepiece 204 engages a flange 240 which is attached to the sheath238. Thus, the endoscope 201, and the sheath 248 of the retractableelectrode assembly 202 are both insertable within the portion 228 of theirrigation and evacuation assembly 203.

Each of two RF electrodes 250a, 250b is sheathed within its respectiveguide sheath 248a, 248b. Although the illustrated embodiment depicts twoRF electrodes, it will be appreciated that the assembly 202 could haveone or more than two electrodes. Each electrode 250a, 250b includes afirst or distal end 249a, 249b, a second, or proximal end 247a, 247b,and a central portion (not shown) disposedly connected therebetween. Acoating of insulation 246 is disposed onto the bare electrode 250. Theinsulation coating 246 may be in the form of a tube of material (such asteflon) heat shrunk around the bare electrode 250. Alternately, theinsulating coat 246 may be powder deposited, using vacuum depositiontechniques, onto the bare electrode 250. In either case, nearly theentire length of the bare electrode 250 is covered by the insulatingcoat 246.

The electrodes 250a, 250b have a generally constant diameter throughoutits entire length and are sized such that they can be slid within thesheaths 248a, 248b. That is, there exists a sufficient clearance (e.g.0.005 inch) between the outside diameter of each of the insulating coats246a, 246b of the electrodes 250a, 250b and the inner diameter of therespective sheaths 248a, 248b. Each electrode 250a, 250b is made from asuperelastic metal material, e.g. typically a Nickel-Titanium (NiTi)metal alloy. The guide sheaths 248a, 248b are made from a rigid plasticor coated metal tubing which forms a rigid conduit that guides, i.e.deforms, the electrode along a predetermined path.

As best seen in FIG. 19, the electrodes 250a, 250b and their respectivesheaths 248a, 248b are contained within the cross sectional envelope ofthe portion 228. Thus, the required incision into the patient need onlyaccommodate the cross sectional area of the portion 228. The presence ofthe extendable electrodes does not increase the size of the requiredincision. It should be also noted that each electrode 250a, 250bdescends downwardly into the field of view of the endoscope 201. In thismanner the surgeon is able to view the extension of each electrode 250a,250b beyond the end of the sheath 248a, 248b.

The two electrodes 250a, 250b and their respective insulators 246a, 246bare encased within their respective guide sheaths 248a, 248b which areencased within a plastic insulating covering 244. The electrodes 250aand 250b encased within the plastic covering 244 exits the housing 232through the opening in the flange 242.

Each electrode 250a, 250b is in parallel electrical communication with atissue impedance measuring device 284 and a R.F. energy source 285. Thecovering 244 enters the movement mechanism 236 through an opening 260formed in a sleeve 256 of the mechanism 236. The electrodes 250a, 250band their respective insulators 246a, 246b exit from the covering 244and each of the second ends 247a, 247b, of each of the electrodes 250a,250b are attached to connecting pins 272a, 272b, respectively. Theconnecting pins 272a, 272b are mounted at an end of a plunger 264. Eachconnecting pin 272a, 272b is in communication with a wire 274a, 274beach of which passes through the plunger 264, through an opening 278,and into an insulated line 276 which is terminated in a plug 280 whichis matingly engagable with a receptacle 282 of the tissue impedancemeasuring device 284. The R.F. source 285 is in electrical communicationwith the impedance measuring device via electrical lines 283a and 283b.The source 285 and the impedance measuring device 284 are connectable inparallel in order to get realtime impedance measurement of tissueengaged between the first ends 249a, 249b of each of the electrode 250a,250b.

The movement mechanism 236 includes a finger ring portion 252, and athumb ring portion 254. The finger ring portion 252 is a generally flatplate having finger loops 251a, 251b formed therein. A passage 262 isformed through the finger ring portion 252 such that the longitudinalaxis of the passage 262 is disposed between each finger loop and liescoplanar with the plane of each finger loop. The sleeve 256, and acylinder 258 are partially inserted into opposite ends of the passage262. The sleeve 256 has a passage longitudinally formed therein so as toreceive the covering 244. The cylinder 258 has a passage longitudinallyformed therein which is aligned with the passage of the sleeve. Theplunger 264 is slidable within the passage of the cylinder 258. One endof the plunger is attached to the thumb ring portion 254, and theconnection pins 272a, 272b are mounted to the other end of the plunger264. The outer surface of the plunger 264 is visible through an accesscutout 270 formed in the cylinder 258. In one embodiment, an indicatorpost 266 is attached to the outer surface of the plunger 264 and passesthrough the access cutout 270 to give an immediate visual, indication ofthe position of the plunger 264 within the cylinder 258. In a preferredembodiment, the outer surface of the plunger 264 is scored with aplurality of indicator marks 268 to provide a visual indication of theposition of the plunger 264 within the cylinder 258, which correspondsvariable length of extension of each of the electrodes beyond theirrespective insulating sheaths.

In operation, the irrigation and evacuation valves, and the endoscopeoperate as described above. Regarding the retractable electrode assembly202, a free hand of the surgeon is used to operate the movementmechanism 236. The surgeon's fingers are engaged within the finger ringloops and the thumb is engaged within the thumb ring portion. The thumbeither pushes or pulls on the thumb ring thereby moving the attachedplunger 264 into or out of the cylinder 258 and the passage 262. As theplunger 264 moves each of the first ends 249a, 249b of each of theelectrodes 250a, 250b move because the connection pins 272a, 272bmounted to the plunger are attached to each of the second ends 247a,247b of each of the electrodes 250a, 250b. Thus, as the plunger moves inthe direction of the arrow A, the central portions of each of theelectrodes moves within their respective insulators in the direction ofthe arrow B, and the first ends 249a, 249b move in the direction of thearrow C.

FIG. 21 illustrates the first end 249 of the electrode 250. The guidesheath 248 is formed with a bend at one end. The electrode 250 slideswithin the sheath 248 and exits the sheath 248 under the guidance of thesheath 248. The insulating cover 246 permits the easy sliding of theelectrode within the sheath 248. Although a bend of 90 degrees isillustrated, it will be appreciated that a bend of any angle may beformed in the sheath 248 so as to guide the electrode 250 into a varietyof angular dispositions. It should be noted that the electrode 250 isbare in the vicinity of the first end 249. A predetermined length valueL, measured from the tip of the electrode to the end 255 of theinsulating coat 246, represents the length of the electrode 250 that isbare or uncoated. Typical values for L range from 0 to 3 cm.

The first ends of each electrode extends beyond its respective sheath248 by a length greater than the predetermined extension length L inorder to permit the bare electrode to penetrate a tissue portion up tothe full L value. Further, the first ends of each needle electrode areseparated by a predetermined separation width W (typically 0.1-2.0 cm)and each first end forms a predetermined angle θ with respect to thelongitudinal axis of portion 228. In the illustrated embodiment, theangle θ is 90 degrees. Typical values for θ range between 0 and 360degrees.

During surgical procedures, the tip end 230 of the portion 228 of theinstrument 200 is brought adjacent to a target tissue area of the bodycavity. The first ends of each electrode are extended beyond theirrespective sheaths such that each first end is embedded into the softtarget tissue area thereby defining a tissue portion engaged between theadjacent first ends of each electrode. The power source is energized andR.F. energy is transmitted from one electrode to the adjacent electrode.The energy transmission causes a coagulation of the tissue portionengaged between the adjacent electrodes and ablation of the targettissue.

Using the present invention, the surgeon can predict and control theamount of tissue ablation/coagulation with greater accuracy and safety.As described above, the spacing between the two parallel first ends ofeach electrode remains constant at some predetermined W value, e.g. 1.0cm. Also, the extension of the electrodes beyond the insulators at agiven angle, i.e. the depth of penetration of each first ends of eachelectrode into the soft tissue portion, can be precisely controlled byobserving the indicator marks on the plunger. Predictable and precisetissue ablation is therefore possible with the present invention becausethe depth of each first end of each electrode in soft tissue can beprecisely controlled by the surgeon. That is, the surgeon can predict acylindrical zone of ablation by controlling the depth of the retractablefirst ends into the soft tissue portion. This precise depth controlenables the surgeon to predict the zone of ablation with greateraccuracy and safety than prior art non-retractable monopolar RF devices,or prior art laser delivery systems.

The cellular structure of body tissue contains water which is aconductor of electrical energy. Consequently, a portion of body tissuealso has an associated resistance or impedance value. In prior artmonopolar electrode devices, tissue impedance is difficult to measure.However, in the present invention, precise impedance measurement of thesoft tissue in the proximity of the bipolar electrodes is possible. Inthe present invention, during the tissue coagulation processsimultaneous measurement of the impedance of the tissue engaged betweenthe extended first ends of the electrodes signals the completion of thetissue coagulation process and provides assurance and confirmation tothe surgeon.

R.F. energy applied to the tissue engaged between the first ends of thetwo electrodes causes the tissue to coagulate which decreases the watercontent associated with the tissue. As the water content decreases theconductivity of the tissue decreases. For a constant R.F. energy, as theconductivity decreases the impedance (or resistance) associated with thetissue increases. The tissue impedance is highest when the tissue iscompletely coagulated, since coagulated tissue has a minimum amount ofwater content and current flow is blocked from one electrode to theother electrode. However, at the beginning of the ablation procedure,the tissue impedance is at a minimum because the water content of thetissue is at its highest level and the tissue is a good conductor andallows the maximum current to flow from one electrode to the other.During the ablation procedure, as the tissue coagulates the watercontent decreases and the tissue impedance increases. The tissueimpedance measurement device 284 can be designed to transmit an variablefrequency audible signal, i.e. a beeping tone, when the tissue impedanceis at its lowest value. As more tissue is ablated and as the tissueimpedance reaches its highest value the audible signal decreases infrequency. In the present invention, the tissue impedance is monitoredor measured on a relative basis. That is, the impedance measured ormonitored is the impedance of the tissue engaged between the two needleelectrodes.

FIG. 22A through 22H illustrate alternate electrode configurations. Itwill be noted that the preferred embodiment of the present inventionincludes two electrodes with a θ of 90 degrees, and a L value of 0-3 cm,and a W value of 0.1-2.0 cm. It will be appreciated that a variety ofelectrode configurations, with associated L, W, and θ values within theabove specified ranges, are possible. However, it is generallypreferable to limit the total number of electrodes to six or less.

It will be noted that in the embodiments illustrated in FIG. 22A-22C,22G-22H, the electrodes 250 are guided by the shape of the sheath 248.That is, the electrodes can be directed towards or away from each otherif the guide sheaths are angled towards or away from each other.Similarly, different θ values are possible if the sheaths are formedwith the appropriately angled bends.

However, in the embodiments illustrated in FIG. 22D-22F, the sheaths aresubstantially straight and the electrodes themselves are bent in orderto direct them in certain orientations. This feature is more clearlyshown in FIG. 23 which illustrates a typical electrode having a bendformed at the location depicted by numeral 257. When the electrode isdisposed within the sheath 248, the electrode 250 is in contact with atleast one portion 259 of the inner surface of the sheath 248 because ofthe bend 257. When the electrode is extended beyond the sheath (shown inphantom lines), the electrode "flattens" within the sheath 248 while theelectrode tip angles away from the sheath centerline in accordance withthe bend 257 formed in the electrode.

FIG. 24 illustrates a retractable electrode surgical instrument 300which is an alternate embodiment of the retractable electrode instrument200 (FIG. 17). The instrument 300 includes many of the same elements asthe instrument 200. These identical elements are identified with thesame reference numeral as shown in FIG. 17. In this embodiment, eachelectrode 250a, 250b is enclosed within a bendable guiding sheath 290a,290b. A guide wire 293a, 293b is disposed within each sheath 290a, 290band includes a first end 289a, 289b and a second end 291a, 291b. Eachfirst end 289 of each guide wire 293 is attached (e.g. welded oradhesively bonded) to an inner surface of a bendable or bellows portion292 of the sheath 290 at a location proximate the open end of the sheath290. Each second end 291 is attached to a lever or knob 294 which ismounted to an outer surface of a housing 291. The housing 291 is similarto the housing 232 and includes communication ports for an irrigationvalve and an evacuation valve (neither shown). In operation, when thereis no tension on the guide wires the sheaths are straight within theconduit, i.e. θ is 0 degrees. As the surgeon pulls back on the knob orlever, the wires are tensioned and the tips of each sheath is pulledback as illustrated until a desired θ value is obtained. In thisembodiment, both the L and the θ values can be adjusted by the surgeonin situ.

With reference to FIG. 25, alternative embodiments for the electrodes ofthe present invention are shown. FIG. 25(a) illustrates an electrodeconfiguration similar to that shown in FIG. 22(a) except that two pairsof bipolar electrodes 350a and 350b are used. FIG. 25(a) shows theelectrodes 350(a) and 350(b) extending outward from sheaths 348(a) and348(b) at the distal end 349. Electrodes 350(a) are preferably eitherboth active or both passive, while the pair of electrodes 350b encasedin sheaths 348b have the opposite polarity. Alternatively, theelectrodes can have cross-polarity. The configuration shown in FIG.25(a) creates an approximately square or rectangular pattern ofelectrodes (depending upon spacing of 350a and 350b). The sheaths andelectrodes are shown bent at an angle of approximately 90 degrees, butother angles are useful as well, and are included in the spirit of theinvention. Although four sheath and electrode pairs are described withtwo as preferably receiving the active voltage/power and the other twoas ground, or i.e. passive, various other combinations are possible andincluded in the invention. A few of these possibilities are illustratedthrough use of FIGS. 25(b)-25(f) which show views of the ends of thesheaths and electrodes, omitting other details for clarity. For example,FIG. 25(b) illustrates the arrangement of electrodes in FIG. 25(a). Withelectrodes 350(a) active and 350(b) passive, electric fields will extendbetween the two pairs approximately as shown by the dotted lines. Thetissue will be heated in a volume having a cross section which can beseen to be an approximate square or rectangular, depending on thespacing of the electrodes. The pattern for two electrodes (i.e. abipolar electrode) is shown in FIG. 25(c). The volume of tissue ablationis controlled by the depth of insertion of the needle electrodes intothe tissue.

Another alternative is shown in FIG. 25(d) in which two passiveelectrodes 350a are used with a third active electrode 350b, resultingin a generally circular cross sectional area of tissue ablation. Use ofmore electrodes will provide a more circular cross-section. As examples,FIGS. 25(e) and 25(f) are further variations which result in circulartissue ablation, both utilizing an active electrode 350b surrounded bypassive electrodes 350a. In all of the above described configurations,energy is passed from one electrode or electrodes to another electrodeor electrodes, through tissue in between, causing it to be heated. Thepreferred number of passive electrodes for circular tissue coagulationis in the range from 3 up to a maximum of 16. For optimal distributionof energy from the electrodes, it is preferred that the sum of areas ofthe active electrodes (designated as 350b in FIG. 25) be approximatelyequal to the sum of the areas of the passive electrode(s) 350a.

FIG. 26 shows an embodiment of the present invention providing acircular zone of coagulation of adjustable diameter. Active electrode350b is surrounded in a circular pattern by passive electrodes 352.Electrodes 352 are superelastic metal "memory wires" such asnickel-titanium wires which are pre-tensioned to a bowed shape or angle.While the electrodes are inside of tubes 354, they are held in straightposition. When the electrodes are advanced outside of tubes 354, theyangle outward from the central axis of the supporting tube 354.Electrode 350b is straight and preferably carries the active energy fromthe RF power source. In operation, the electrodes 352 and 350b are allconnected to the electrode moving mechanism 236 (FIG. 20) and moved inand out together. Alternately, electrode 350b may be independently movedrelative to the other electrodes 352, thus allowing for significantflexibility in adjusting the area of ablation or coagulation. Forclarity of illustration, only a portion of the tubes and electrodes isshown. The assembly is shown cut off at 355, but actually extends inlength, the electrodes 352 and 350b having a proximal end (not shown)which connects to the electrode moving mechanism, which in turn connectsthe electrodes to an RF energy source, for transmitting the power to thedistal ends at 353. The dashed lines in FIG. 26(a) illustrate themovement of electrodes 350b and 352, the central electrode 350b beingcoaxial with the central axis and preferably extending or retractingindependently of electrodes 352. As shown by the dashed lines,electrodes 352 may be extended outward and away from electrode 350b, thegreater extension providing a greater cross-section ofablation/coagulation. The end of central electrode 350b is extended intothe same plane as the ends of electrodes 352 for coagulation of a volumeof tissue having a circular cross sectional area.

Use of superelastic "memory wires" which exit the tubes 354 atpredetermined angles is preferred. Another method of angling theelectrodes outward is more clearly shown in FIG. 26(b) illustrating oneof the tubes 354 with an electrode 352 installed therein. Thepre-induced angle of electrode 352 causes it to bear against theinterior wall 356 and the rim 358 of the opening 360. The structure oftube 354 and electrode 352 combination (as shown in the figure) requirestube 354 to be constructed of an electrically insulating material sinceno coating is shown on electrode 352. Alternatively, or in addition tohaving tube 354 non-conductive, the electrode wires can be insulatedwith a thin non-conductive coating except for the end portion of thewires. In this manner, the only active portions of the electrodes arethose portions which do not have the non-conductive coating.

FIG. 26(a) shows a grouping of six tubes enclosing electrodes 352, andone tube with an electrode 350b. Although six tubes 352 are shown, theinvention also includes other numbers of tubes, electrodes, andconfigurations, including such configurations corresponding to thepatterns illustrated in FIGS. 25(b) to 25(f). Arrangement of electrodesin a different pattern can be done to obtain coagulation of a volume oftissue having a rectangular, circular or other cross section. As analternate construction, the tubes 354 and 362 could be merged in onecontinuous piece of material with the required bores for guiding theelectrodes formed therethrough. Such an embodiment would look similar tothe cylindrical section of the embodiment to be described in FIG. 27.Note that the further the electrodes are advanced out of the tubes intobody tissue, the greater will be the volume of tissue coagulated, as thetissue provides a conductive path for the RF energy along the lengths ofthe electrodes inserted in the tissue.

Referring now to FIG. 27, there is shown an alternate embodiment foraccomplishing a similar purpose as presented in regard to the embodimentof FIG. 26. Instead of angular memory wire electrodes, all of electrodes366 are straight, and preferably constructed of superelastic conductivematerial, such as nickel titanium wire. Electrodes 366 as well ascentral electrode 368 are all guided by holes 370 through the firstsection 372 of the guiding structure 373. The structure 373 has aconical shaped end section 374, the narrow end of which is connected toa first end face 376 from which electrodes 366 emerge, and extends fromthe face 376 to a wide end 378 from which the central electrode 368emerges. The conical shape 374 interferes with the electrodes 366,deflecting them outward from the central axis 375 away from the centralelectrode 368. This provides a method for varying the angle ofdeflection from the central axis, and thereby achieving a larger orsmaller cross section of tissue coagulation, with end sections usingdifferent angles for the conical shape.

As with the embodiment of FIG. 26, the further the electrodes 366 areprotruded from the casing 372, the farther they extend from the centralelectrode 368, creating a larger area of ablation/coagulation. Theelectrodes' proximal ends at 380 are to be connected to an electrodemovement mechanism such as 236 shown in FIG. 20.

FIG. 28 illustrates a connecting cable assembly 394 for an RF generatorsystem utilizing the apparatus above described, and additionally has thefacility for providing either monopolar RF power to the electrodes fortissue cutting/coagulation or bipolar power for coagulation procedures.The use of the monopolar RF power between two electrodes in closeproximity has not been addressed in the prior art, and will be shown tohave significant advantages. In the prior art, monopolar electrodes havebeen used with a patient return pad to complete the electrical path.Monopolar applications use higher RF power, typically for tissue cuttingand coagulation. The use of patient return pads creates an electricalpath from the active monopolar electrode to the return pad. This paththerefore tends to be relatively long, unpredictable, and unsafe.

The single connecting cable system shown in FIG. 28 allows the surgeonto use one instrument either in monopolar or bipolar mode. The singlecable system also eliminates the need for patient return grounding padsand the associated risk of "stray currents" and adjacent tissue damage.In FIG. 28, cable assembly 394 includes two bipolar cables 396 and 398having banana plugs 400 and 402, each of the cables 396 and 398 leadingfrom an interconnection block 404. The banana plugs 400 and 402 are forinterconnection with bipolar receptacles 406 and 408 of RF generator410. There is a monopolar output cable 412 leading from theinterconnection block 404 with a monopolar plug 414 for interconnectionwith monopolar receptacle 416 of the RF generator 410 (receptacle 416 istypically labelled "Foot Control" in commercially available RFgenerators). A return path cable 418 is shown leading from theinterconnection block 404, and has a connector 420 for mating withreceptacle 422 of the RF generator 410 (receptacle 422 is typicallylabelled "Patient Return"). The function of the interconnection block isto join the bipolar cables 396 and 398 to the monopolar output cable 412and return path cable 418. The block 404 then connects the resultant twowires to an output cable 424 which passes the RF power through aconnector assembly 425 to electrode movement mechanism 236 which in turnconnects the power to the electrodes.

The RF generator 410 is a standard energy source in the industry, andhas facility for switching the power output either to the higher powerlevel for use in the monopolar mode for cut/coagulation, or to the lowerpower bipolar mode for coagulation. FIG. 28 also shows a standard footpedal 426 interconnected with the RF power generator 410 through cable428 for turning the RF power output of the generator 410 off or on incut or coagulation mode.

The above described cable assembly is used with the above describedendoscopic surgical instrument to allow either monopolar or bipolarpower to be supplied to the electrodes without having to manuallyconnect and disconnect separate cables to RF generator 410.

The convenience of being able to select either monopolar or a bipolarenergy for application to a single electrode assembly gives a surgeonsignificantly enhanced surgical capability and convenience. In themonopolar mode, ablation and removal of tissue is possible, and in thebipolar mode, coagulation is possible, allowing the surgeon to makedecisions after insertion of a single electrode apparatus. Previously,use of electrodes in bipolar and monopolar modes required time consumingremoval of electrodes and complete change of operating procedures andinstrumentation.

Method For Removing Uterine Fibroids

Over thirty percent of women between 30 and 50 years of age have uterinefibroids, which can cause abnormal bleeding and associated problems.There are three major kinds of fibroids: (1) subserosal fibroids whichare located outside the wall of the uterus; (2) intramural fibroidswhich are located inside the uterine wall; and (3) submucosal fibroidswhich are located outside the endometrium. The majority of fibroidsneeding treatment to prevent abnormal bleeding are the submucosal type.Treatment options for uterine fibroids have included drug therapy andsurgical treatment. Drug therapy is used to shrink the fibroid, but isexpensive and fibroids return to their original size within four monthsof ceasing use of the drug therapy. Surgical treatment such asmyomectomy or hysterectomy involve significant hospital stay andrecovery time as well as high costs. Alternative treatments thereforeare preferred to drug therapy or surgical treatment.

Laparoscopic myoma coagulation is used for the treatment of subserosaland intramural fibroids. Submucosal fibroids cannot be treatedlaparoscopically due to the need for an internal incision and closure ofthe uterine wall. Laparoscopic coagulation uses a Nd:YAG laser orbipolar/monopolar electrosurgical electrodes to shrink the fibroids.

The prior art use of R.F. needle electrodes for laparoscopic coagulationhas been limited to a single monopolar electrode or to a pair of bipolarelectrodes for laparoscopic treatment of uterine fibroids because theprior art electrodes can only be used along the axis of visualization ofthe laparoscope. Additionally, the prior art single monopolar or pair ofbipolar electrodes have provided only a limited area of tissuecoagulation. The electrodes of the present invention as described above,provide a larger zone of coagulation, and may be used for laparoscopicor hysteroscopic treatment of uterine fibroids. The needle electrodesdescribed herein may be introduced to the sidewall of the uterus at anyangle to the axis of visualization of the hysteroscope.

The flexible needle electrodes of the present invention allow the angleof entry to tissue (relative to the axis of the probe) to be adjusted toany angle. Moreover, the use of multiple electrodes with an adjustableangle of entry to tissue, allows a larger sized area of tissuecoagulation, including areas which have greater area than the size ofthe probe which guides the needle electrodes to the tissue insertionsite.

The present invention treats uterine fibroids with hysteroscopicmyolysis. The uterine fibroids are first identified using hysteroscopy,endovaginal ultrasound, computerized axial tomography, or MRI to allowvisualization of the interior of the uterine cavity. By such imaging ofthe uterine cavity, the size, shape and position of any fibroid can bedetermined. Hysteroscopic myolysis can then be performed using amonopolar needle electrode, or one of the bipolar needle electrodeconfigurations of the present invention as above described. To protectthe rectum, bladder and blood vessels of the uterus, vaginal ultrasoundis used to determine the fibroid's posterior surface prior to insertionof the electrode(s). The R.F. needle electrodes are then insertedthrough an operating hysteroscope. The electrodes can then bemanipulated and inserted in the fibroids to the desired depth underdirect visualization of the hysteroscope, and the area surrounding theelectrodes may be coagulated. By repeatedly puncturing the fibroid withthe needle electrodes, the entire fibroid can be coagulated.

This disclosure addresses uterine fibroid treatment in particular.However, the method described can be used for ablation/removal of anysoft tissue, such as breast, liver, colon, and prostate tumors/growths.

Although the present invention has been described above in terms of aspecific embodiment, it is anticipated that alterations andmodifications thereof will no doubt become apparent to those skilled inthe art. It is therefore intended that the following claims beinterpreted as covering all such alterations and modifications as fallwithin the true spirit and scope of the invention.

What is claimed is:
 1. An endoscopic surgical instrument comprising:a) ahousing; b) a single access conduit being disposed within said housing,and having a proximal conduit end and a distal conduit end; c) anirrigation port formed in said housing; d) an evacuation port formed insaid housing, each of said irrigation and said evacuation ports being influid communication, through independent valves, with said proximalconduit end of said single access conduit; e) an aperture and a closuretherefor, said aperture being formed in said housing, and said closurebeing openable to allow the ingress of microsurgical instrumentationinto said proximal conduit end of said single access conduit; and f) RFelectrode means insertable into said aperture and into said singleaccess conduit and having a length so as to protrude beyond said distalconduit end of said single access conduit, said RF electrode means forengaging a body tissue portion, and for simultaneously ablating saidbody tissue portion and measuring an impedance value associated withsaid body tissue portion, said RF electrode means including at leastthree electrodes in a non-linear pattern.
 2. An endoscopic surgicalinstrument as recited in claim 1, wherein said RF electrode meansincludes electrode movement means for extending and retracting one ormore of said electrodes beyond said distal end.
 3. An endoscopicsurgical instrument as recited in claim 2, wherein each of saidelectrodes has a distal electrode end, and wherein said electrode meansfurther includes electrode diverting means for causing said distalelectrode end of one or more of said electrodes to move away from one ormore of the other said electrodes.
 4. An endoscopic surgical instrumentas recited in claim 3 wherein said diverting means includes a conicallytapered guide for deflecting said electrodes as said electrodes areextended by said movement means, whereby as said electrodes areextended, said distal electrode ends of said electrodes are spacedfurther apart.
 5. An endoscopic surgical instrument as recited in claim3 wherein said diverting means includesa) one or more of said electrodesbeing memory electrodes constructed of memory wire and preconfigured ina non-linear shape; and b) electrode casing means having one or moreguiding passageways with a proximal opening and a distal opening forguiding said memory electrodes;whereby when one of said memoryelectrodes has a portion extended by said movement means beyond saiddistal opening of said casing means, said portion returns to thepre-configured shape.
 6. An endoscopic surgical instrument as recited inclaim 1 wherein said RF electrode means further includesa) casing meansfor guiding said electrodes, said casing means with a proximal openingand a distal opening; b) insulation means for electrically insulatingportions of said electrodes; and c) said electrodes including two usagecategories including one or more first type electrodes, and one or moresecond type electrodes, where active RF energy is passed on one type ofelectrodes and the other type is used for an electrical return path. 7.An endoscopic instrument as recited in claim 6 wherein said RF electrodemeans further includes electrode diverting means for causing a portionof one or more of said first type electrodes to move away from one ormore of said second type electrodes.
 8. An endoscopic surgicalinstrument as recited in claim 7 wherein said electrode diverting meansincludessaid casing means having a tapered extension protruding fromsaid distal end,whereby said portions of one or more of said first typeelectrodes protruding from said distal end are deflected.
 9. Anendoscopic surgical instrument as recited in claim 7 wherein saidelectrode diverting means includesone or more of said first typeelectrodes being memory electrodes constructed of memory wire andpreconfigured in a non-linear shape, whereby when a said memoryelectrode has a portion extended by said movement means beyond saiddistal end of said casing means, said portion returns to said non-linearshape and said electrode is deflected.
 10. An endoscopic surgicalinstrument as recited in claim 8 whereinsaid diverting means is aconically tapered section having a central axis and extending from saidcasing means so as to deflect said electrodes of said first type outwardand away from said central axis when said electrodes are extended bysaid movement means, and said conically tapered section having a saidpassageway therethrough along said central axis for passage of anelectrode of said second type,whereby as said electrodes are extended bysaid movement means an increasingly larger area of ablation isachievable when RF energy is applied to said electrodes, passing fromsaid electrodes of said first type, through body tissue and to saidelectrode of said second type.
 11. An RF electrode assembly as recitedin claim 7 whereinsaid diverting means is a conically tapered sectionhaving a central axis and extending from said casing means so as todeflect said electrodes of said first type outward and away from saidcentral axis when said electrodes are extended by said movement means,and said conically tapered section having a passageway therethroughalong said central axis for passage of an electrode of said secondtype,whereby as said electrodes are extended by said movement means anincreasingly larger area of ablation is achievable when RF energy isapplied to said electrodes, passing from said electrodes of said firsttype, through body tissue and to said electrode of said second type. 12.An RF electrode assembly for ablating a body tissue portion,comprising:a) at least three electrodes arranged in a non-linearpattern; and b) electrode movement means for extending and retractingone or more of said electrodes.
 13. An RF electrode assembly as recitedin claim 12 wherein each of said electrodes has a proximal electrode endand a distal electrode end, and said RF electrode assembly furthercomprising:electrode diverting means for causing said distal electrodeend of one or more of said electrodes to move away from one or more ofthe other said electrodes.
 14. An RF electrode assembly as recited inclaim 13 wherein said diverting means includes a conically tapered guidefor deflecting said electrodes as said electrodes are extended by saidmovement means, whereby as said electrodes are extended, tips of saidelectrodes are spaced further apart.
 15. An RF electrode assembly asrecited in claim 13 wherein said diverting means includesa) one or moreof said electrodes being memory electrodes constructed of memory wireand preconfigured in a non-linear shape; and b) electrode casing meanshaving one or more guiding passageways with a proximal opening and adistal opening for guiding said memory electrodes,whereby when one ofsaid memory electrodes has a portion extended by said movement meansbeyond said distal end of said casing means, said portion returns to thepre-configured shape.
 16. An RF electrode assembly as recited in claim12 wherein said RF electrode means further includesa) casing means forguiding said electrodes, said casing means with a proximal opening and adistal opening; b) insulation means for electrically insulating portionsof said electrodes; and c) said electrodes including two usagecategories including one or more type A electrodes, and one or more typeB electrodes, where active RF energy is passed on one of the types andthe other type is used for an electrical return path.
 17. An RFelectrode assembly as recited in claim 16 wherein said electrode meansfurther includes electrode diverting means for causing a portion of oneor more of said electrodes to move away from one or more of the otherelectrodes.
 18. An RF electrode assembly as recited in claim 17 whereinsaid electrode diverting means includessaid casing means having atapered extension protruding from said distal end,whereby said portionof one or more of said electrodes protruding from said distal end aredeflected.
 19. An RF electrode assembly as recited in claim 17 whereinsaid electrode diverting means includesone or more of said electrodesbeing memory electrodes constructed of memory wire and preconfigured ina non-linear shape,whereby said memory electrode has a portion extendedby said movement means beyond said distal end of said casing means, saidportion returns to said non-linear shape and said electrode isdeflected.
 20. A method for soft tissue ablation/removal, comprising:(a)directing an endoscopic instrument including RF electrode means to thetarget tissue; (b) advancing said RF electrode means into said tissue,said electrode means comprising at least three electrodes arranged in anon-linear pattern to engage a volume of tissue between said electrodes;(c) providing RF energy to said electrodes, thereby ablating/removingsaid tissue.